Hello, sorry for replying so late but I was away on a trip n_n'
Actually no, I contacted Esoteric privately about that too but they need to see some test code using those animations and my coder hasn't been able to prepare such an example. If you ask me, the issue has nothing to do with the code since it appears in Spine editor, but I haven't had time to investigate more. On the other hand, Erikari once told me they do have some issues with mixing in 3.7 so maybe that's that. I should really pester them again about it since I have that snap live in the game and it bothers me :/
Will keep you updated in case there's development!